<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>

<body>
    <script>
        // boolean 代表空 否定值会转换成false 例如""、0、NaN、null、undefined
        // false
        console.log(Boolean(""));
        // false
        console.log(Boolean(0));
        // false
        console.log(Boolean(NaN));
        // false
        console.log(Boolean(null));
        // false
        console.log(Boolean(undefined));
        // true
        console.log(Boolean("小白"));
        // true
        console.log(Boolean("12"));
    </script>
</body>

</html>